Disabling means for a friction device operating mechanism



Feb. 7, 1967 Q. a. FITES 33%,536

DISABLING MEANS FOR A FRICTION DEVICE OPERATING MECHANISM Filed May 28, 1964 INVENTOR CYRIL B. FITES United States Patent O 3,302,536 DISABLING MEANS FOR A FRICTION DEVICE OPERATING MECHANISM Cyril B. Fites, St. John, Mo., assignor to Wagner Electric Corporation, St. Louis, Mo., a corporation of Delaware Filed May 28, 1964, Ser. No. 370,848 4 Claims. (Cl. 92-130) This invention relates to friction device operating mechanism having resiliently urged means therein for mechanically energizing a friction device and in particular to novel emergency release or disabling means for disabling said resiliently urging means.

In the past, the fluid pressure braking systems of heavy duty vehicles were equipped with friction device operating mechanisms having resiliently urged means responsive to fluid pressure supplied thereto less than a predetermined amount from a source of said fluid pressure to mechanically effect emergency energization of a friction device, and said friction device operating mechanism was also provided with a friction device actuator responsive to fluid pressure metered thereto to effect normal or service energization of said friction device. Of course, the mechanical energization of the vehicle friction device under emergency conditions by the aforementioned resiliently urged means often occurred at inopportune times which might place the vehicle in a dangerous position with respect to other vehicles; therefore, it is mandatory to provide disabling means for disabling or releasing the force of said resiliently urged means under such emergency conditions to provide for movement of the vehicle to a more convenient or safer position in order to correct the deficiencies in the vehicle fluid pressure system which effected the reduction of fluid pressure below the predetermined amount resulting in the emergency function of the resiliently urged means. One of the dis advantages or undesirable features of such past disabling means was that a plug, boot or other such closure member was necessarily removably secured to the friction device operating mechanism to prevent entry of foreign particles or dirt into the interior thereof through an opening in said friction device operating mechanism providing access to said disabling means for driving tool insertion purposes. Of course, such removably secured closure members were easily lost, and in many instances not replaced through negligence or the like, thereby providing an entry through the unprotected access opening for foreign particles or dirt which seriously impaired the effectiveness and fluid pressure integrity of the friction device operating mechanism. Other past disabling means were removably secured in the friction device operating mechanism access opening and invertible into driving engagement with said resiliently urged means; however, such invertible disabling means were also often displaced from the access opening through vibration, road shock, etc., and through negligence also lost or not replaced after use.

An object of the present invention is to provide disabling means for a friction device operating mechanism which overcomes the aforementioned undesirable features.

Another object of the present invention is to provide novel emergency release or disabling means for disabling resiliently urged means operable in a friction device operating mechanism in response to the failure of fluid pressure applied thereto from a source of said fluid pressure applied thereto from a source of said fluid pressure to mechanically energize a friction device.

Another object of the present invention is to provide a disabling means for a friction device operating mechanism which inherently forms a closure for said friction device operating mechanism.

3,3@2,535 Patented Feb. 7, i967 "ice Another object of the present invention is to provide disabling means for a friction device operating mechanism which obviates the necessity of a closure member or other means to prevent the entry of foreign material or particles, such as dirt, into said friction device operating mechanism.

Another object of the present invention is to provide means for disabling the resiliently urged friction device energizing means of a friction device operating mechanism wherein said disabling means is normally biased to a position disengaged from said resiliently urged means and movable in response to an applied force into driving engagement therewith.

And still another object of the present invention is to provide a novel disabling means or emergency release mechanism for a friction device operating mechanism which is economically manufactured and easily assembled in a friction device operating mechanism.

These and other objects and advantages of the present invention will become apparent hereinafter.

Briefly, the invention embodies resiliently urged emergency release or disabling means for operative connection with resiliently urged means of a friction device operating mechanism to release or contain the friction device energizing force thereof, said resiliently urged means being utilized to mechanically energize a friction device in response to fluid pressure supplied thereto from a fluid pressure source less than a predetermined magnitude.

In the drawing which illustrates embodiments of the invention,

FIGURE 1 is a diagrammatic view of a fluid pressure system having a friction device operating mechanism embodying the present invention shown therein, and

FIGURE 2 is a greatly enlarged cross-sectional view of the friction device operating mechanism shown in FIGURE 1.

Referring now to FIGURE 1 in detail, a friction device actuating system, indicated generally at 1, is provided with fluid pressure generating means, such as compressor 2, which is connected to an inlet 3 of a charging or control valve 4 by a conduit 5, and a fluid pressure storage reservoir 6 is interposed in the conduit 5 providing, in combination with said compressor, a source of fluid pressure. Another conduit 7 is interposed between an outlet 8 of the charging valve 4 and the emergency port of a friction device operating mechanism or actuating cylinder 9. The charging valve 4 is provided with rotatable passage means 10 connecting the inlet 3 with the outlet 8; however, said passage means can be rotated clockwise to a position interrupting pressure fluid communication between said inlet and outlet and establishing pressure fluid communication between said outlet and an eX- haust port 11 to vent said outlet to atmosphere. A conduit 12 has one end intersecting the conduit 5 and the other end thereof connecting with the inlet side of an application valve 13, and another conduit or service line 14 is interposed between the outlet or service side of said application valve and the service or inlet port of the actuating cylinder 9. To complete the system 1, a push rod of the actuating cylinder 9 is pivotally connected with linkage means or an actuating lever, such as slack adjuster 15, for energizing a friction device (not shown).

The actuating cylinder 9, FIGURE 2, is provided with a housing 16 having an annular Wall 17 therein interposed between a bore 18 and a tapered bore 19, and an aperture or bore 20, having an Oring seal 21 sealably disposed therein, is provided through the wall 17. A service or inlet port 22 which receives the conduit 14, as previously mentioned, is provided in the housing 16 connecting with the tapered bore 19, and an emergency port 23 which receives the conduit '7, as previously mentioned, connects with the bore 18. The housing 16 is provided 3 with a peripheral flange 24 on the leftward end thereof, and a concave or dish-shaped end plate or fixed housing 25 is provided with a centrally located aperture 26 therein and a peripheral flange 27 positioned in opposed relalation with the flange 24. The end plate housing 25 is also provided with a plurality of mounting studs 28 for connection with a cooperating mounting bracket (not shown) on or adjacent to the friction device.

A conventional, releasable clamping band 29 is positioned in clamping engagement with the opposed peripheral flanges 24, 27 serving to maintain a peripheral bead 30 of a diaphragm 31 in sealable abutting engagement therebetween, and an actuating or service chamber 32 is formed in the housing tapered bore 19 between the diaphragm 31 and the wall 17 in pressure fluid communication with the service port 22. A push rod 33 extends coaxially through the end plate aperture 26 having an exterior or working end pivotally connected with the slack adjuster 15, as previously mentioned, and an interior end biased into engagement with the diaphragm 31 by the compressive force of a return spring 34 interposed between the end plate 25 and said push rod.

The larger portion of a stepped emergency or power piston 35 is slidably received in the housing bore 18 having an O-ring seal 36 disposed in the peripheral portion thereof in sealable engagement with said housing bore, and the smaller portion thereof is slidably received in the wall bore 20 in scalable engagement with the O-ring seal 21 therein, said piston defining in said housing bore 18 an expansible fluid pressure emergency chamber 37 in pressure fluid communication with emergency port 23. The smaller portion of the stepped piston 35 is provided with a working end or end Wall positioned in said actuating chamber 32 normally in abutting engagement with the diaphragm 31. A centrally located, integrally formed extension or projection 38 is provided on the smaller portion of the piston 35 having a threaded bore 39 therein, and a threaded extension or stud 40 is threadedly received in said piston extension bore and retained therein against displacement by a lock nut 41 threadedly received on said stud in locking engagement with the rightward or free end of said piston extension.

A removable base wall or closure member 42 is slidable in the housing bore 18 and retained therein against displacement by a groove and lock ring assembly 43 provided in the rightward end of said housing bore 18. The compressive force of emergency springs 44, 45 interposed between the piston 35 and the closure member 42 serves not only to bias said piston in a leftwardly or working direction but also serves to bias said closure member into abutting engagement with the retaining ring 43 which retains said closure member against displacement from the rightward end of the housing bore 18. A wedge or radially extending projection 46 connected with the closure member 42 extends into a slot 47 provided in the rightward end of the housing 16 to prevent rotation of said closure member in the housing bore 18', and an aperture 48 is provided in said closure member being substantially coaxial with the threaded stud 49 of the piston 35.

Emergency release or disabling means, indicated generally at 49, is provided with a body portion 50 having a peripheral surface 51 slidable in the closure member aperture 48 in such a manner as to prevent the entry of foreign particles into the interior of said closure member and housing bore 18. A hexagonal or tool receiving flange 52 is provided on the rightward or exterior end of the body 50 having a radial shoulder or bearing surface 53 thereon for bearing engagement with the closure member 42 about the aperture 48 thereof, and a threaded, axial bore 54 is provided through the leftward or interior end of said body for threaded driving engagement with the piston extension 40. To complete the description of the actuating cylinder 9, a retainer or abutment member 55 is fixedly positioned adjacent to the interior end of the body 50 by a snap ring and groove assembly 56, provided on said body interior end, and a spring 57 is biased between said abutment member and the piston 35 normally urging said abutment member to a position in abutting engagement with the closure member 42 wherein the interior end of said body is maintained in predetermined spaced relation with the piston extension 40 to effect lost motion therebetween before threaded engagement between the body threaded bore 54 and said piston extension can be effected.

In the operation, with the component parts of the system 1 and actuating cylinder 9 positioned as described and shown in FIGURES l and 2, the fluid pressure in the reservoir 6 and the actuating cylinder emergency chamber 37 is in excess of a predetermined value necessary to create an emergency force when acting on the effective area of the piston 35 in said chamber to overcome the compressive forces of the springs 44, 45 and maintain said piston in its inoperative or non-working position, as shown.

To effect normal or service energization of the friction device (not shown) an applied force on the application valve 13 meters fluid pressure from the reservoir 6 through conduits 5 and 12, said application valve, the conduit 14, and the service port 22 into the service chamber 32 to act in the effective area of the diaphragm 31 creating a service force to move said diaphragm and push rod 33 leftwardly against the return spring 34 thereby rotating the slack adjuster 15 and energizing the friction device (not shown) connected therewith. When the de sired vehicle deceleration or a complete stOp is attained, removal of the applied force from the application valve 13 effects the exhaust of pressure fluid from the service chamber 32 through the service port 22, the conduit 14 and the exhaust of said application valve to atmosphere thereby eliminating the service force. Upon the elimination of the service force, the return spring 34 serves to return the push rod 33 and diaphragm 31 to their normal positions thereby providing for de-energization of the friction device.

In an emergency condition when the fluid pressure in the reservoir 6 and actuating cylinder emergency chamber 37 is reduced to a value less than the predetermined value clue to leaks in the system 1 or a non-producing compressor 2, or the like, the emergency force opposing the emergency springs 44, 45 is correspondingly reduced, and the compressive force of said emergency springs thereby serves to move the piston 35 from the inoperative position thereof leftwardly toward an operative position in abutting engagement with the housing wall 17. Since the smaller portion of the piston 35 is normally in driving engagement with the diaphragm 31 in the service chamber 32, this leftward movement of said piston by the springs 44, 45 mechanically moves said diaphragm and pushrod 33 leftwardly therewith to rotate the slack adjuster 15 and mechanically effect energization of the friction device connected therewith.

With the component parts of the system 1 and actuating cylinder 9 positioned as above described, the friction device is now mechanically energized to effect an emergency vehicle stop. As previously mentioned hereinbefore, such emergency stops can occur at inopportune times and place the vehicle in a dangerous position with respect to other vehicles on the road; there-fore, upon such emergency stops, it is often advantageous to move the vehicle to a less dangerous .position in order to correct the failure of the system 1 and subsequently reestablish normal operating conditions wherein the system fluid pressure is greater than the predetermined value.

Disabling or emergency release means 49 are provided to overcome the above-described emergency function of the actuating cylinder 9 by containing or releasing the force of the emergency springs 44, 45 which, in conjunction with the resiliently urged piston 35, serves to mechanically energize the friction device under such emergency conditions, as follows. An axially directed, manually applied force on the exterior end of the body 50 of the disabling means 49 slides said body leftwardly against the spring 57 in the closure member aperture 48 until the interior end of said body is moved into lost motion engagement with the stud 40. A rotative or twisting force is then manually applied on the flange 52 at the exterior end of the body 50 to threadedly engage the body bore 54 with the threaded stud 40 and further move said body leftwardly until the flange shoulder 53 is moved into bearing engagement with the closure member 42 about the aperture 48 therein. With the body bore 54 threadedly engaged with the stud 40 and the flange shoulder 53 in bearing engagement with the closure member 42, a subsequent manual force applied by a tool, such as a wrench or the like (not shown), on the body flange 52 effects further threaded engagement between said body bore and stud which serves to move the piston 35 rightwardly against the force of the emergency springs 44, 45 toward the inoperative position thereof. When the piston 35 is moved by the dis abling means 49 a predetermined distance toward the inoperative position thereof, the mechanical friction device energizing force of the springs 44, 45 and said piston is sufliciently overcome to deenergize the friction device so that the vehicle can be moved to a more advantageous and far less dangerous position. Of course, the return spring 34 effects rightward movement of the component parts associated therewith in follow-up relation with the working end of the piston 35 to rotate the slack adjuster and de-energize the friction device. With the force of the springs 44, 45 so contained between the closure member 42 and the piston 35 through the substantially rigid, threaded interconnection of the disabling means 49 and stud 40, the clamping band 29 can be removed to replace or service the various parts in the actuating chamber 32 without fear of the housing 16 being expelled from the end plate by the force of said springs 44, 45. Further, the rigidly interconnected closure member 42 and piston 35 can be removed from the housing bore 18 upon removal of the split retaining ring 43 without fear of expulsion since the compressive forces of the springs 44, are positively contained.

When the fluid pressure failure of the system -1 has been corrected and the fluid pressure in the reservoir 6 and actuating cylinder emergency chamber 37 is increased to a value in excess of the predetermined value wherein normal operating conditions are now re-estab lished, the emergency force is correspondingly increased and serves to maintain the piston 35 in its inoperative position against the emergency spring force. In this event, the disabling means body can now be rotated out of threaded engagement with the stud 40', and the disabling means return spring 57 thereafter slidably moves said disabling means body in the closure member aperture 48 to its original position with the abutment member engaged with the closure member 42 to prevent displacement of said disabling means body from said closure member aperture.

The operator may initiate the emergency function of the actuating cylinder 9, if desired, by dynamiting the system 1. To dynamite the system '1, the operator merely rotates the rotatable passage means 10 of the charging valve 4 in a clockwise direction to a position aligned between the outlet 8 and exhaust .port 11 thereby exhausting pressure fluid from the emergency chamber 37 through the emergency port 23 into the conduit 7 and therefrom via said outlet, passage means and exhaust port of the charging valve 4 to the atmosphere. With the emergency chamber 37 vented to atmosphere, the emergency function of the actuating cylinder 9 is initiated, as described hereinbefore, to energize the friction device.

From the foregoing, it is now apparent that a novel disabling means for a friction device operating mechanism meeting the objects set out hereinbefore is provided and that changes or modifications as to the precise configurations, shapes and details of the construction set forth in the disclosure by way of illustration may be made by those skilled in the art without departing from the spirit of the invention as defined by the claims which follow.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a friction device operating mechanism having a housing, resiliently urged means movable in said housing toward an operative position for energizing a friction device in response to fluid pressure less than a predetermined value supplied to said resiliently urged means from a source of said fluid pressure and also movable toward an inoperative position in said housing when the fluid pressure supplied thereto exceeds the predetermined value, means =for disabling said resiliently urged means comprising a disabling member slidable in said housing, a force responsive end on said disabling member exteriorly of said housing, a driving end on said disabling member interiorly of said housing for driving engagement with said resiliently urged means when said resiliently urged means is in its operative position, and spring means biased between said resiliently urged means and said driving end to normally urge said driving end toward a position predeterminately spaced from said resiliently urged means to prevent interfering engagement therewith when said resiliently urged means is in its inoperative position, said disabling member being movable against said spring means in response to an applied force on the force responsive end thereof to drivingly engage said driving end with said resiliently urged means when said resiliently urged means is in its operative position and move said force responsive end into bearing engagement with said housing, and said disabling member being thereafter movable in response to the applied force to drive said resiliently urged means against said spring means toward its inoperative position to mechanically de-energize the friction device.

2. In the friction device operating mechanism accord ing to claim 1 wherein said driving end includes an abutment member removably secured to said disabling member and extending radially outwardly thereof for abutting engagement with said housing and seating engagement with said spring means.

3. In a friction device operating mechanism having a housing, resiliently urged means movable in said housing toward a friction device energizing position in response to fluid pressure less than a predetermined value supplied to said resiliently urged means from a source of said fluid pressure and said resiliently urged means also being movable in said housing toward a friction device d e-energizing position when the fluid pressure supplied to said resiliently urged means exceeds the predetermined value, means for disabling said resiliently urged means and defining with said housing a closure to prevent the entry of foreign particles thereinto including a disabling member slidable in said housing between an operative position in bearing engagement with said housing and in driving engagement with said resiliently urged means when said resiliently urged means is in its friction device energizing position and an inoperative position in abutting engagement with said housing and in predetermined spaced relation out of interfering engagement with said resiliently urged means when said resiliently urged means is in its friction device de-energizing position, and spring means biased between said resiliently urged means and said disabling member and normally urging said disabling member toward its inoperative position, said disabling member being movable against said spring means in response to an applied force thereon from its inoperative position to its operative position, and said disabling member being thereafter further movable in response to the applied force while in its operative position to mechanically drive said resiliently urged means toward its friction device de'energizing position and against said spring means.

4. In a friction device operating mechanism having a housing, resiliently urged means movable in said housing toward a friction device energizing position in re-- sponse to fluid pressure less than a predetermined value supplied to said resiliently urged means from a source of said fluid pressure and said resiliently urged means also being movable toward a friction device de-energizing position in said housing when the fluid pressure supplied to said resiliently urged means exceeds the predetermined value, extension means on said resiliently urged means including a threaded portion, an opening in said housing substantially coaxial with said extension means, means for disabling said resiliently urged means and defining with said housing a closure to prevent the entry of foreign particles t hereinto including a disabling member slidable in said opening between an operative position in mechanical driving engagement with said resiliently urged means and in bearing engagement with said housing when said resiliently urged means is in its friction device energizing position and an inoperative position in abutment with said housing and in predetermined spaced relation out of interfering engagement with said resiliently urged means when said resiliently urged means is in its friction device de-energizing position, a force responsive end on said disabling member exteriorly of said housing including flange means for bearing engagement with said housing about said opening, another end on said disabling member opposite said force responsive end and interiorly of said housing including displacement preventing means for abutment with said housing about said opening, a bore in said disabling member having a threaded portion for threaded engagement with said threaded portion of said extension means, and spring means biased between said resiliently urged means and said other end of said disabling member to normally urge said disabling member toward its inoperative position engaging said displacement preventing means with said housing and maintaining said other end in predetermined spaced relation and out of interfering engagement with said threaded extension when said resiliently urged means is in its friction device de-ener-gizing position, said disabling member being movable in said opening against said spring means in response to an applied force on said force responsive end toward its operative position to threadedly engage said threaded portion of said bore with said threaded portion of said extension means when said resiliently urged means is in its friction device energizing position until said flange means is moved into bearing engagement with said housing, and said disabling member being thereafter further movable in response to the applied force to effect further threaded engagement of said bore and extension means to mechanically drive said resiliently urged means against said spring means toward its friction device de-energizing position.

References Cited by the Examiner UNITED STATES PATENTS 1,125,521 1/1915 Harrison 173-169 3,090,359 5/1963 Hoppenstand 92-64 3,10l,2l9 8/1963 Herrera 9263 3,240,129 3/1966 Cruse 92130 References Cited by the Applicant UNITED STATES PATENTS 2,754,805 7/ 1956 Beman. 2,976,085 3/ 1961 Grogan. 2,992,630 7/1961 Leighton et al. 3,020,094 2/1962 Murty et al. 3,095,--67 6/1963 Murty et al. 3,101,219 8/1963 Herrera. 3,107,583 10/1963 Woodward. 3,109,347 11/1963 Brodl et al. 3,112,959 12/ 1963 Kateley. 3,117,496 1/1964v Dobrikin.

MARTIN P. SCHWADRON, Primary Examiner.

SAMUEL LEVINE, Examiner. 

1. IN A FRICTION DEVICE OPERATING MECHANISM HAVING A HOUSING, RESILIENTLY URGED MEANS MOVABLE IN SAID HOUSING TOWARD AN OPERATIVE POSITION FOR ENERGIZING A FRICTION DEVICE IN RESPONSE TO FLUID PRESSURE LESS THAN A PREDETERMINED VALUE SUPPLIED TO SAID RESILIENTLY URGED MEANS FROM A SOURCE OF SAID FLUID PRESSURE AND ALSO MOVABLE TOWARD AN INOPERATIVE POSITION IN SAID HOUSING WHEN THE FLUID PRESSURE SUPPLIED THERETO EXCEEDS THE PREDETERMINED VALUE, MEANS FOR DISABLING SAID RESILIENTLY URGED MEANS COMPRISING A DISABLING MEMBER SLIDABLE IN SAID HOUSING, A FORCE RESPONSIVE END ON SAID DISABLING MEMBER EXTERIORLY OF SAID HOUSING, A DRIVING END ON SAID DISABLING MEMBER INTERIORLY OF SAID HOUSING FOR DRIVING ENGAGEMENT WITH SAID RESILIENTLY URGED MEANS WHEN SAID RESILIENTLY URGED MEANS IS IN ITS OPERATIVE POSITION, AND SPRING MEANS BIASED BETWEEN SAID RESILIENTLY URGED MEANS AND SAID DRIVING END TO NORMALLY URGE SAID DRIVING END TOWARD A POSITION PREDETERMINATELY SPACED FROM SAID RESILIENTLY URGED MEANS TO PREVENT INTERFERING ENGAGEMENT THEREWITH WHEN SAID RESILIENTLY URGED MEANS IS IN ITS INOPERATIVE POSITION, SAID DISABLING MEMBER BEING MOVABLE AGAINST SAID SPRING MEANS IN RESPONSE TO AN APPLIED FORCE ON THE FORCE RESPONSIVE END THEREOF TO DRIVINGLY ENGAGE SAID DRIVING END WITH SAID RESILIENTLY URGED MEANS WHEN SAID RESILIENTLY URGED MEANS IS IN ITS OPERATIVE POSITION AND MOVE SAID FORCE RESPONSIVE END INTO BEARING ENGAGEMENT WITH SAID HOUSING, AND SAID DISABLING MEMBER BEING THEREAFTER MOVABLE IN RESPONSE TO THE APPLIED FORCE TO DRIVE SAID RESILIENTLY URGED MEANS AGAINST SAID SPRING MEANS TOWARD ITS INOPERATIVE POSITION TO MECHANICALLY DE-ENERGIZE THE FRICTION DEVICE. 